The present invention relates to a method for fabricating a buried metallic layer in a semiconductor body and a semiconductor component having a buried metallic layer.
It is known that the behavior of semiconductor components can be influenced by the provision of buried metallic layers arranged in semiconductor regions of the components.
In this respect, reference is made to DE 100 01 869 A1, by way of example, which describes a MOSFET which blocks in both directions and in the body zone of which a metallic layer is arranged. Said metallic layer acts as a recombination zone for free charge carriers in the body zone and reduces the current gain of a parasitic bipolar transistor formed by the body zone, the source zone and the drain zone of the MOSFET.
The recombination effect of metals can also be utilized in components which comprise a plurality of components arranged in a semiconductor layer or a substrate and in which the individual components are in each case insulated from one another by pn junctions. In the case of such components, it is possible, depending on the external circuitry, for minority charge carriers to be injected through individual components into the substrate, which lead to shunt currents in the substrate. Said shunt currents can adversely influence the function of other components arranged in the substrate. This problem area is described for example in DE 199 53 333 A1 or DE 100 14 659 C2, which propose producing a recombination zone in the substrate by implanting or introducing metal atoms. An improved recombination effect could be achieved in this case by means of a metallic layer in the substrate.